Coronary bypass is the surgical treatment for coronary heart disease, and is used to relieve angina pectoris and prevent myocardial infarction. One or more blood vessels, usually an artery in the chest or a vein from the leg, are transplanted (grafted) to create new paths for blood to flow from the aorta to the heart muscle, bypassing obstructed sections of the coronary arteries. Saphenous veins are commonly used as bypass conduits in coronary bypass grafting.
Saphenous veins are either of two chief superficial veins of the leg. The vein, which originates in the foot and passes up the medial side of the leg and through the saphenous opening to join the femoral vein, is called either the internal saphenous vein or the long saphenous vein. The other vein originates similarly and passes up the back of the leg to join the popliteal at the knee, which is called either the external saphenous vein or the short saphenous vein. These veins are harvested from the leg and attached to the heart's circulatory system to bypass arteries that are not providing sufficient blood flow.
Aortacoronary bypass surgery means that one or more bypass grafts are implanted between the aorta and the coronary blood vessel. If occlusive vascular disease limits the blood flow to the heart, the bypass graft bridges the occluded, or diseased, heart blood vessel (coronary artery), and brings new blood to the heart. Saphenous veins (from the leg) or arteries (like the internal mammary artery) are commonly used as grafts for coronary bypass surgery. All bypasses were originally performed using the saphenous vein from the leg to carry blood around the obstruction. The vein was attached at one end to the aorta and at the other end to the coronary artery distal to the blockage or occlusion could be considered.
The procedure for harvesting the veins involves an incision made close to the knee to identify the saphenous vein and introduce the endoscope. Additional small “stab” incisions may be made at the ankle or at the groin to retrieve the harvested vein. A fiber optic endoscope is introduced through the incision at the knee to allow the doctor to view and harvest the vein from the inner thigh and/or calf, depending on the surgeon's preference for the vein conduit. Exploration of either area is accomplished by blunt dissection aided by CO2 insluffation. Branches of the saphenous vein are divided by cautery. The vein is then removed through the tiny incisions at the ankle or groin.
This vein on the inside of the leg running from the ankle to the groin can be used to make bypasses from the aorta to the coronary arteries. There is a deep venous system that normally does most of the work draining blood from the legs back to the heart. The saphenous vein is part of the superficial system that normally does only about 10% of the work. The saphenous vein can, therefore, be taken out without harming the patient or adversely affecting the leg. An endoscopic instrument is introduced through these upper incisions to allow the doctor to view the inside of the inner calf. Instruments are then introduced through the incisions that explore the area, close off the ends of the veins that will remain in the leg, and cut the vein. The vein is then removed through small incisions at the ankle or at the knee. The incisions described are then closed, typically using conventional sutures, and the leg is cleaned.
It is common for the leg from which the vein is harvested to swell slightly. Trauma to the leg during this part of the procedure causes blood to ooze from the subcutaneous tissue. Accumulation of blood in the leg wound tunnels during coronary artery bypass is exacerbated by the requirement for anticoagulation. The blood is removed from inside the leg to avoid blood collection, possible infection and pain. Furthermore, it is desirable to remove the fluids to facilitate healing.
Blood is currently removed from the leg by having the surgeon or surgical assistant roll up a piece of gauze, place the gauze on the calf, and roll it down the leg manually while applying pressure so that the blood will drain from the lower incision site. This procedure is repeated during the surgery until the completion of surgery.
None of the above inventions, taken either singularly or in combination, is seen to describe the instant invention as claimed.